PROJECT SUMMARY ? Project 4 Cigarette smoking during pregnancy increases risk for catastrophic pregnancy complications, growth retardation, other adverse fetal and infant health problems, and later-in-life chronic conditions among exposed offspring. The most effective intervention for reducing smoking during pregnancy is a behavioral economic model wherein participants earn incentives (e.g., vouchers exchangeable for goods and services) contingent on objective evidence of smoking abstinence. However, incentive-based interventions are typically delivered in relatively intense protocols requiring frequent clinic visits, which limits the geographical range over which services can be delivered and potentially denies treatment to those residing in remote or otherwise difficult to reach settings. The proposed study will examine the feasibility, efficacy, and cost-effectiveness of a smartphone-based financial incentives intervention whereby smoking monitoring and delivery of incentives are completed remotely using a mobile app. Pregnant women will be recruited via obstetrical clinics, WIC offices, and ads in print and online media outlets in all Vermont counties outside of those immediately adjacent to our research clinic. Eligible participants who complete the informed consent process will be randomized to one of two conditions: an incentives condition wherein women will receive financial incentives contingent on the remote submission of breath and saliva specimens indicating abstinence from recent smoking, or a control condition in which women will receive current best practices for smoking cessation (i.e., referral to the VT pregnancy-specific quit line). Outcomes will include point prevalence smoking abstinence at assessments conducted in late pregnancy and 4-, 8-, 12-, and 24-weeks postpartum, continuous abstinence during antepartum and postpartum, birth outcomes (birth weight, gestational age at delivery, NICU admissions), and perceived barriers and facilitators of treatment engagement. If successful, the proposed smartphone-based financial incentives intervention has the potential to substantially expand the reach of this effective intervention for pregnant smokers. It is also likely to facilitate my successful progress towards becoming an independent investigator.